diff --git a/public/script.js b/public/script.js
index 57acf537e..405319c55 100644
--- a/public/script.js
+++ b/public/script.js
@@ -2705,8 +2705,7 @@ export async function generateQuietPrompt(quiet_prompt, quietToLoud, skipWIAN, q
             quietName: quietName,
         };
         originalResponseLength = responseLengthCustomized ? saveResponseLength(main_api, responseLength) : -1;
-        const generateFinished = await Generate('quiet', options);
-        return generateFinished;
+        return await Generate('quiet', options);
     } finally {
         if (responseLengthCustomized) {
             restoreResponseLength(main_api, originalResponseLength);
@@ -3361,9 +3360,9 @@ export async function generateRaw(prompt, api, instructOverride, quietToLoud, sy
 
         let data = {};
 
-        if (api == 'koboldhorde') {
+        if (api === 'koboldhorde') {
             data = await generateHorde(prompt, generateData, abortController.signal, false);
-        } else if (api == 'openai') {
+        } else if (api === 'openai') {
             data = await sendOpenAIRequest('quiet', generateData, abortController.signal);
         } else {
             const generateUrl = getGenerateUrl(api);
@@ -3376,13 +3375,15 @@ export async function generateRaw(prompt, api, instructOverride, quietToLoud, sy
             });
 
             if (!response.ok) {
-                const error = await response.json();
-                throw error;
+                throw await response.json();
             }
 
             data = await response.json();
         }
 
+        // should only happen for text completions
+        // other frontend paths do not return data if calling the backend fails,
+        // they throw things instead
         if (data.error) {
             throw new Error(data.response);
         }
@@ -4434,6 +4435,11 @@ export async function Generate(type, { automatic_trigger, force_name2, quiet_pro
         return Promise.resolve();
     }
 
+    /**
+     * Saves itemized prompt bits and calls streaming or non-streaming generation API.
+     * @returns {Promise<void|*|Awaited<*>|String|{fromStream}|string|undefined|Object>}
+     * @throws {Error|object} Error with message text, or Error with response JSON (OAI/Horde), or the actual response JSON (novel|textgenerationwebui|kobold)
+     */
     async function finishGenerating() {
         if (power_user.console_log_prompts) {
             console.log(generate_data.prompt);
@@ -4545,6 +4551,12 @@ export async function Generate(type, { automatic_trigger, force_name2, quiet_pro
 
     return finishGenerating().then(onSuccess, onError);
 
+    /**
+     * Handles the successful response from the generation API.
+     * @param data
+     * @returns {Promise<String|{fromStream}|*|string|string|void|Awaited<*>|undefined>}
+     * @throws {Error} Throws an error if the response data contains an error message
+     */
     async function onSuccess(data) {
         if (!data) return;
 
@@ -4554,6 +4566,7 @@ export async function Generate(type, { automatic_trigger, force_name2, quiet_pro
 
         let messageChunk = '';
 
+        // if an error was returned in data (textgenwebui), show it and throw it
         if (data.error) {
             unblockGeneration(type);
             generatedPromptCache = '';
@@ -4668,9 +4681,15 @@ export async function Generate(type, { automatic_trigger, force_name2, quiet_pro
         return Object.defineProperty(new String(getMessage), 'messageChunk', { value: messageChunk });
     }
 
+    /**
+     * Exception handler for finishGenerating
+     * @param {Error|object} exception Error or response JSON
+     * @throws {Error|object} Re-throws the exception
+     */
     function onError(exception) {
+        // if the response JSON was thrown (novel|textgenerationwebui|kobold), show the error message
         if (typeof exception?.error?.message === 'string') {
-            toastr.error(exception.error.message, t`Error`, { timeOut: 10000, extendedTimeOut: 20000 });
+            toastr.error(exception.error.message, t`Text generation error`, { timeOut: 10000, extendedTimeOut: 20000 });
         }
 
         generatedPromptCache = '';
@@ -5338,6 +5357,7 @@ function setInContextMessages(lastmsg, type) {
  * @param {string} type Generation type
  * @param {object} data Generation data
  * @returns {Promise<object>} Response data from the API
+ * @throws {Error|object}
  */
 export async function sendGenerationRequest(type, data) {
     if (main_api === 'openai') {
@@ -5357,12 +5377,10 @@ export async function sendGenerationRequest(type, data) {
     });
 
     if (!response.ok) {
-        const error = await response.json();
-        throw error;
+        throw await response.json();
     }
 
-    const responseData = await response.json();
-    return responseData;
+    return await response.json();
 }
 
 /**
@@ -5394,6 +5412,7 @@ export async function sendStreamingRequest(type, data) {
  * Gets the generation endpoint URL for the specified API.
  * @param {string} api API name
  * @returns {string} Generation URL
+ * @throws {Error} If the API is unknown
  */
 function getGenerateUrl(api) {
     switch (api) {
diff --git a/public/scripts/extensions/stable-diffusion/index.js b/public/scripts/extensions/stable-diffusion/index.js
index 15611e878..b175860c8 100644
--- a/public/scripts/extensions/stable-diffusion/index.js
+++ b/public/scripts/extensions/stable-diffusion/index.js
@@ -2373,6 +2373,7 @@ function ensureSelectionExists(setting, selector) {
  * @param {string} [message] Chat message
  * @param {function} [callback] Callback function
  * @returns {Promise<string|undefined>} Image path
+ * @throws {Error} If the prompt or image generation fails
  */
 async function generatePicture(initiator, args, trigger, message, callback) {
     if (!trigger || trigger.trim().length === 0) {
@@ -2391,7 +2392,7 @@ async function generatePicture(initiator, args, trigger, message, callback) {
     trigger = trigger.trim();
     const generationType = getGenerationType(trigger);
     const generationTypeKey = Object.keys(generationMode).find(key => generationMode[key] === generationType);
-    console.log(`Generation mode ${generationTypeKey} triggered with "${trigger}"`);
+    console.log(`Image generation mode ${generationTypeKey} triggered with "${trigger}"`);
 
     const quietPrompt = getQuietPrompt(generationType, trigger);
     const context = getContext();
@@ -2428,6 +2429,8 @@ async function generatePicture(initiator, args, trigger, message, callback) {
 
     try {
         const combineNegatives = (prefix) => { negativePromptPrefix = combinePrefixes(negativePromptPrefix, prefix); };
+
+        // generate the text prompt for the image
         const prompt = await getPrompt(generationType, message, trigger, quietPrompt, combineNegatives);
         console.log('Processed image prompt:', prompt);
 
@@ -2438,11 +2441,16 @@ async function generatePicture(initiator, args, trigger, message, callback) {
             args._abortController.addEventListener('abort', stopListener);
         }
 
+        // generate the image
         imagePath = await sendGenerationRequest(generationType, prompt, negativePromptPrefix, characterName, callback, initiator, abortController.signal);
     } catch (err) {
         console.trace(err);
-        toastr.error('SD prompt text generation failed. Reason: ' + err, 'Image Generation');
-        throw new Error('SD prompt text generation failed. Reason: ' + err);
+        // errors here are most likely due to text generation failure
+        // sendGenerationRequest mostly deals with its own errors
+        const reason = err.error?.message || err.message || 'Unknown error';
+        const errorText = 'SD prompt text generation failed. ' + reason;
+        toastr.error(errorText, 'Image Generation');
+        throw new Error(errorText);
     }
     finally {
         $(stopButton).hide();
@@ -2513,7 +2521,7 @@ function restoreOriginalDimensions(savedParams) {
  */
 async function getPrompt(generationType, message, trigger, quietPrompt, combineNegatives) {
     let prompt;
-
+    console.log('getPrompt: Generation mode', generationType, 'triggered with', trigger);
     switch (generationType) {
         case generationMode.RAW_LAST:
             prompt = message || getRawLastMessage();
@@ -2729,7 +2737,7 @@ async function sendGenerationRequest(generationType, prompt, additionalNegativeP
             throw new Error('Endpoint did not return image data.');
         }
     } catch (err) {
-        console.error(err);
+        console.error('Image generation request error: ', err);
         toastr.error('Image generation failed. Please try again.' + '\n\n' + String(err), 'Image Generation');
         return;
     }
diff --git a/public/scripts/horde.js b/public/scripts/horde.js
index 1e0141fb0..0b5d94bea 100644
--- a/public/scripts/horde.js
+++ b/public/scripts/horde.js
@@ -181,6 +181,14 @@ function setContextSizePreview() {
     }
 }
 
+/** Generates text using the Horde API.
+ * @param {string} prompt
+ * @param params
+ * @param signal
+ * @param reportProgress
+ * @returns {Promise<{text: *, workerName: string}>}
+ * @throws {Error}
+ */
 async function generateHorde(prompt, params, signal, reportProgress) {
     validateHordeModel();
     delete params.prompt;
diff --git a/public/scripts/openai.js b/public/scripts/openai.js
index 959a87571..da1d950cd 100644
--- a/public/scripts/openai.js
+++ b/public/scripts/openai.js
@@ -1313,6 +1313,11 @@ export async function prepareOpenAIMessages({
     return [chat, promptManager.tokenHandler.counts];
 }
 
+/**
+ * Handles errors during streaming requests.
+ * @param {Response} response
+ * @param {string} decoded - response text or decoded stream data
+ */
 function tryParseStreamingError(response, decoded) {
     try {
         const data = JSON.parse(decoded);
@@ -1324,6 +1329,9 @@ function tryParseStreamingError(response, decoded) {
         checkQuotaError(data);
         checkModerationError(data);
 
+        // these do not throw correctly (equiv to Error("[object Object]"))
+        // if trying to fix "[object Object]" displayed to users, start here
+
         if (data.error) {
             toastr.error(data.error.message || response.statusText, 'Chat Completion API');
             throw new Error(data);
@@ -1339,15 +1347,22 @@ function tryParseStreamingError(response, decoded) {
     }
 }
 
-async function checkQuotaError(data) {
-    const errorText = await renderTemplateAsync('quotaError');
-
+/**
+ * Checks if the response contains a quota error and displays a popup if it does.
+ * @param data
+ * @returns {void}
+ * @throws {object} - response JSON
+ */
+function checkQuotaError(data) {
     if (!data) {
         return;
     }
 
     if (data.quota_error) {
-        callPopup(errorText, 'text');
+        renderTemplateAsync('quotaError').then((html) => Popup.show.text('Quota Error', html));
+
+        // this does not throw correctly (equiv to Error("[object Object]"))
+        // if trying to fix "[object Object]" displayed to users, start here
         throw new Error(data);
     }
 }
@@ -1766,6 +1781,15 @@ async function sendAltScaleRequest(messages, logit_bias, signal, type) {
     return data.output;
 }
 
+/**
+ * Send a chat completion request to backend
+ * @param {string} type (impersonate, quiet, continue, etc)
+ * @param {Array} messages
+ * @param {AbortSignal?} signal
+ * @returns {Promise<unknown>}
+ * @throws {Error}
+ */
+
 async function sendOpenAIRequest(type, messages, signal) {
     // Provide default abort signal
     if (!signal) {
@@ -2028,12 +2052,13 @@ async function sendOpenAIRequest(type, messages, signal) {
     else {
         const data = await response.json();
 
-        await checkQuotaError(data);
+        checkQuotaError(data);
         checkModerationError(data);
 
         if (data.error) {
-            toastr.error(data.error.message || response.statusText, t`API returned an error`);
-            throw new Error(data);
+            const message = data.error.message || response.statusText || t`Unknown error`;
+            toastr.error(message, t`API returned an error`);
+            throw new Error(message);
         }
 
         if (type !== 'quiet') {
diff --git a/public/scripts/slash-commands/SlashCommandBrowser.js b/public/scripts/slash-commands/SlashCommandBrowser.js
index 51b0bac1b..916f65441 100644
--- a/public/scripts/slash-commands/SlashCommandBrowser.js
+++ b/public/scripts/slash-commands/SlashCommandBrowser.js
@@ -1,5 +1,4 @@
 import { escapeRegex } from '../utils.js';
-import { SlashCommand } from './SlashCommand.js';
 import { SlashCommandParser } from './SlashCommandParser.js';
 
 export class SlashCommandBrowser {
@@ -30,7 +29,7 @@ export class SlashCommandBrowser {
                                 this.details?.remove();
                                 this.details = null;
                                 let query = inp.value.trim();
-                                if (query.slice(-1) == '"' && !/(?:^|\s+)"/.test(query)) {
+                                if (query.slice(-1) === '"' && !/(?:^|\s+)"/.test(query)) {
                                     query = `"${query}`;
                                 }
                                 let fuzzyList = [];
@@ -59,7 +58,7 @@ export class SlashCommandBrowser {
                                         cmd.helpString,
                                     ];
                                     const find = ()=>targets.find(t=>(fuzzyList.find(f=>f.test(t)) ?? quotedList.find(q=>t.includes(q))) !== undefined) !== undefined;
-                                    if (fuzzyList.length + quotedList.length == 0 || find()) {
+                                    if (fuzzyList.length + quotedList.length === 0 || find()) {
                                         this.itemMap[cmd.name].classList.remove('isFiltered');
                                     } else {
                                         this.itemMap[cmd.name].classList.add('isFiltered');
@@ -78,7 +77,7 @@ export class SlashCommandBrowser {
                         list.classList.add('autoComplete');
                         this.cmdList = Object
                             .keys(SlashCommandParser.commands)
-                            .filter(key => SlashCommandParser.commands[key].name == key) // exclude aliases
+                            .filter(key => SlashCommandParser.commands[key].name === key) // exclude aliases
                             .sort((a, b) => a.toLowerCase().localeCompare(b.toLowerCase()))
                             .map(key => SlashCommandParser.commands[key])
                         ;
@@ -97,7 +96,7 @@ export class SlashCommandBrowser {
                                         }
                                     }
                                 }
-                                if (this.details != details) {
+                                if (this.details !== details) {
                                     Array.from(list.querySelectorAll('.selected')).forEach(it=>it.classList.remove('selected'));
                                     item.classList.add('selected');
                                     this.details?.remove();
@@ -124,7 +123,7 @@ export class SlashCommandBrowser {
         parent.append(this.dom);
 
         this.mo = new MutationObserver(muts=>{
-            if (muts.find(mut=>Array.from(mut.removedNodes).find(it=>it == this.dom || it.contains(this.dom)))) {
+            if (muts.find(mut=>Array.from(mut.removedNodes).find(it=>it === this.dom || it.contains(this.dom)))) {
                 this.mo.disconnect();
                 window.removeEventListener('keydown', boundHandler);
             }
@@ -136,7 +135,7 @@ export class SlashCommandBrowser {
     }
 
     handleKeyDown(evt) {
-        if (!evt.shiftKey && !evt.altKey && evt.ctrlKey && evt.key.toLowerCase() == 'f') {
+        if (!evt.shiftKey && !evt.altKey && evt.ctrlKey && evt.key.toLowerCase() === 'f') {
             if (!this.dom.closest('body')) return;
             if (this.dom.closest('.mes') && !this.dom.closest('.last_mes')) return;
             evt.preventDefault();
diff --git a/public/scripts/textgen-settings.js b/public/scripts/textgen-settings.js
index 67e058f08..7b3017efb 100644
--- a/public/scripts/textgen-settings.js
+++ b/public/scripts/textgen-settings.js
@@ -880,6 +880,13 @@ function setSettingByName(setting, value, trigger) {
     }
 }
 
+/**
+ * Sends a streaming request for textgenerationwebui.
+ * @param generate_data
+ * @param signal
+ * @returns {Promise<(function(): AsyncGenerator<{swipes: [], text: string, toolCalls: [], logprobs: {token: string, topLogprobs: Candidate[]}|null}, void, *>)|*>}
+ * @throws {Error} - If the response status is not OK, or from within the generator
+ */
 async function generateTextGenWithStreaming(generate_data, signal) {
     generate_data.stream = true;
 
@@ -995,6 +1002,7 @@ export function parseTabbyLogprobs(data) {
  * @param {Response} response - Response from the server.
  * @param {string} decoded - Decoded response body.
  * @returns {void} Nothing.
+ * @throws {Error} If the response contains an error message, throws Error with the message.
  */
 function tryParseStreamingError(response, decoded) {
     let data = {};
diff --git a/src/endpoints/backends/chat-completions.js b/src/endpoints/backends/chat-completions.js
index 502f3c266..b78ba45b5 100644
--- a/src/endpoints/backends/chat-completions.js
+++ b/src/endpoints/backends/chat-completions.js
@@ -1051,8 +1051,12 @@ router.post('/generate', jsonParser, function (request, response) {
             }
         } catch (error) {
             console.log('Generation failed', error);
+            const message = error.code === 'ECONNREFUSED'
+                ? `Connection refused: ${error.message}`
+                : error.message || 'Unknown error occurred';
+
             if (!response.headersSent) {
-                response.send({ error: true });
+                response.status(502).send({ error: { message, ...error } });
             } else {
                 response.end();
             }
@@ -1068,7 +1072,7 @@ router.post('/generate', jsonParser, function (request, response) {
 
         const message = errorResponse.statusText || 'Unknown error occurred';
         const quota_error = errorResponse.status === 429 && errorData?.error?.type === 'insufficient_quota';
-        console.log(message, responseText);
+        console.log('Chat completion request error: ', message, responseText);
 
         if (!response.headersSent) {
             response.send({ error: { message }, quota_error: quota_error });